Today is the first day of the Taylor Wessing Photographic Portrait Prize 2013 exhibition at the National Portrait Gallery. I have to admit that I was not even aware of this competition until recently when I saw the past catalogues in their bookshop.

I’m not sure it is absolutely necessary to visit this exhibition when compared to the BP Portrait Award. My thinking is that photographic prints can be whatever size you want. There is no reason why it can’t be just as easily appreciated in the catalogue that will accompany the exhibition.

A painting or sculpture is created to a size which the artist has in their mind. If the artwork is to fill the whole side of a building it can never be reproduced in any book or online. You have to be physically there to take in that piece.

I haven’t had a chance to get this year’s catalogue yet to decide which is my favourite. But when the shortlist was published a fews weeks ago, I saw a comment about this competition posted online which said that all the pictures were rubbish and why was an art gallery exhibiting them.

By coincidence this year’s Reith Lectures delivered by the artist Grayson Perry were broadcast recently on BBC Radio on the subject of modern art. So what makes this collection of images worthy of space on a wall in an art gallery?

He takes photography as an example, a form of visual culture he thinks is “pouring into the world like sewage”. He asked his friend – the artist/photographer Martin Parr – what’s the difference between a smartphone snap and a revered photographic artwork.

“When the print is bigger than two metres and costs more than five figures,” Parr replied. An employee of an auction house added that “it helps if it’s in an edition of five”.

Well, is that right? Do photographs need to be printed huge to match the price tag to be called art? Don’t get me wrong, if you have the time to visit this exhibition I’m sure it will be worthwhile. Me? Instead of seeing the exhibition, I’m going to listen to the Reith Lectures by Grayson Perry for the second time.